Headlamp Control, Function - GF82.10-S-2009TRF
Model 447
with code XM0 (Facelift)
except code XM7 (MOPF II)
Function requirements, general
- No overvoltage or undervoltage
Driving lights actuation, general
Driving lights actuation includes all functions which serve the optimum illumination of the road while driving.
The driving lights actuation encompasses the following subfunctions:
- Function sequence for low beam actuation
- Function sequence for high beam actuation
- Function sequence for daytime running lights actuation
- Function sequence for auto on/off driving lights
- Function sequence for headlamp range control
The electronic ignition lock (EZS) control unit (N73) sends the status of terminal 15 over the interior CAN (CAN B) to the signal acquisition and actuation module (SAM) control unit (N10/1).
Model 447.6/7
The driving lights are actuated corresponding to the position of the illumination switch (S1). The signal acquisition and actuation module (SAM) control unit directly reads in the status of the illumination switch.
Model 447.8
The driving lights are actuated corresponding to the position of the illumination switch (S1/2). The signal acquisition and actuation module (SAM) control unit directly reads in the status of the illumination switch.
Additional function requirements for low beams actuation
- Circuit 15 on
During low beams actuation, the standing light actuation is active, this is described in the "Standing/parking lights actuation function" document.
Function sequence for low beam actuation
Turning the illumination switch into the "low beams" position requests actuation of the low beams.
The signal acquisition and actuation module (SAM) control unit directly reads in the status of the illumination switch. It then sends a request to switch on the low beam via the interior CAN, the electronic ignition lock (EZS) control unit and the front end CAN (CAN G) to the left headlamp control unit (E1/1n9). Via the left headlamp LIN (LIN G1) and left front actuation module, LED exterior lighting (E1/1n7), it then actuates the left low beam (short range) (E1/1e15) and the left low beam (long range) (E1/1e16).
The signal acquisition and actuation module (SAM) control unit also sends a request for switching on the low beams via interior CAN, electronic ignition lock (EZS) control unit and front end CAN to the right headlamp control unit (E2/1n9).
Via the right headlamp LIN (LIN G2) and right front actuation module, LED exterior lighting (E2/1 n7), it then actuates the right low beam (short range) (E2/1e15) and the right low beam (long range) (E2/1e16).
On model 447.6/7:
The signal acquisition and actuation module (SAM) control unit also sends the "Low beam indicator lamp" request over the interior CAN to the instrument cluster (IC) control unit (A1/1). This then actuates the low beam indicator lamp (A1/1e67).
On Model 447.8:
The signal acquisition and actuation module (SAM) control unit also sends the "Low beam indicator lamp" request over the interior CAN, the central gateway (N93/4) and the user interface CAN (CAN HMI) to the instrument cluster (IC) control unit. This then actuates the low beam indicator lamp.
Additional function requirements for high beam actuation:
- For high beam function: Terminal 15 ON and low beam ON
- For headlamp flashing function: Terminal 15 R ON
Function sequence for high beam actuation
The high beams actuation is comprised of the following subfunctions:
- Function sequence for high beams
- Function sequence for headlamp flasher
Function sequence for high beams
On vehicles with CODE LG2 (LED Intelligent Light System):
High beam actuation is requested by pushing the combination switch (S4) forward.
The steering column tube module (MRM) control unit (N80) reads in the switch position of the combination switch directly. It sends this via the chassis CAN (CAN E), the electronic ignition lock (EZS) control unit and the interior CAN to the signal acquisition and actuation module (SAM) control unit.
The signal acquisition and actuation module (SAM) control unit sends the "High beams On" request via interior CAN, electronic ignition lock (EZS) control unit and front end CAN to the left headlamp control unit and to the right headlamp control unit. The left headlamp control unit then actuates the left low beam (long range) via left headlamp LIN and left front actuation module, LED exterior lighting. At the same time, the right headlamp control unit actuates the right low beam (long range) via right headlamp LIN and right front actuation module, LED exterior lighting. The low beams (long range) then generate the high beams. The left high beam (E1/1e1) and the right high beam (E2/1e1) are also switched on if necessary.
On model 447.6/7:
The signal acquisition and actuation module (SAM) control unit also sends a "High beam indicator lamp" request over the interior CAN to the instrument cluster (IC) control unit. This then actuates the high beam indicator lamp (A1/1e3).
On Model 447.8:
The signal acquisition and actuation module (SAM) control unit also sends a "High beam indicator lamp" request over the interior CAN, the central gateway and the user interface CAN to the instrument cluster (IC) control unit. This then actuates the high beam indicator lamp.
On vehicles without CODE LG2 (LED Intelligent Light System):
High beam actuation is requested by pushing the combination switch forward.
The steering column tube module (MRM) control unit reads in the switch position of the combination switch directly. It sends this via the chassis CAN, the electronic ignition lock (EZS) control unit and the interior CAN to the signal acquisition and actuation module (SAM) control unit.
The signal acquisition and actuation module (SAM) control unit receives the switch position of the combination switch and actuates the left high beam and the right high beam directly.
On model 447.6/7:
The signal acquisition and actuation module (SAM) control unit also sends the "High beam indicator lamp" status over the interior CAN to the instrument cluster (IC) control unit. This then actuates the high beam indicator lamp.
On Model 447.8:
The signal acquisition and actuation module (SAM) control unit also sends the "High beam indicator lamp" status over the interior CAN, the central gateway and the user interface CAN to the instrument cluster (IC) control unit. This then actuates the high beam indicator lamp.
Function sequence for headlamp flasher
The function sequence and signal path for the headlamp flasher function correspond to that of the high beam function. However, to request the headlamp flasher function, the combination switch must be pulled backward. If the combination switch is pulled back and held, the high beam actuation remains active for maximum 30 s. Then the pending request is interpreted as a "stuck combination switch" and the actuation of the high beams is terminated.
Additional function requirements for daytime running lights actuation:
- "Daytime running lights" function activated in instrument cluster (IC) control unit.
- "Engine running" signal set and vehicle speed > 3 km/h.
- Illumination switch in "AUTO" position
Function sequence for daytime running lights actuation
On model 447.6/7:
The instrument cluster (IC [KI]) control unit sends a request for switching on the daytime running lights via interior CAN to the signal acquisition and actuation module (SAM) control unit.
The CDI control unit (N3/33) (with engine 651) or the CDI control unit (N3/36) (with engine 622.9) or the CDI control unit (N3/40) (with engine 654) or the CDI control unit (N3/50) (with engine 622.8) or the ME control unit (N3/34) (with engine 274) sends the "Engine running" signal via the drive train CAN, the powertrain control unit, the chassis CAN, the electronic ignition lock (EZS) control unit and the interior CAN to the signal acquisition and actuation module (SAM) control unit.
The Electronic Stability Program (ESP) control unit (N30/4) sends the vehicle speed via the chassis CAN, electronic ignition lock (EZS) control unit and interior CAN to the signal acquisition and actuation module (SAM) control unit.
The signal acquisition and actuation module (SAM) control unit evaluates the information. If the function requirements are fulfilled, it sends a request to switch on the daytime running lights over the interior CAN, the electronic ignition lock (EZS) control unit and the front end CAN to the left headlamp control unit and the right headlamp control unit.
On vehicles with CODE LG2 (LED Intelligent Light System):
The left headlamp control unit then actuates the daytime running lights in the left parking/standing/daytime running light (E1/1e13) via left headlamp LIN and left front actuation module, LED exterior lighting.
At the same time, the right headlamp control unit actuates the daytime running lights in the right parking/standing/daytime running light (E2/1e13) via right headlamp LIN and right front actuation module, LED exterior lighting.
The daytime running lights actuation is deactivated as soon as the illumination switch is turned to the standing light, manual driving lights, left parking light or right parking light position.
On vehicles without CODE LG2 (LED Intelligent Light System):
Additional function requirements for automatic driving lights:
- "Engine running" signal set and vehicle speed > 3 km/h.
- Illumination switch in "AUTO" position
The CDI control unit or the ME control unit sends the "Engine running" signal via the drive train CAN, the powertrain control unit, the chassis CAN, the electronic ignition lock (EZS) control unit and the interior CAN to the signal acquisition and actuation module (SAM) control unit.
The Electronic Stability Program (ESP) control unit transmits the vehicle speed via the chassis CAN, the electronic ignition lock (EZS) control unit and the interior CAN to the signal acquisition and actuation module (SAM) control unit.
The signal acquisition and actuation module (SAM) control unit directly reads in the status of the illumination switch.
On Model 447.8:
The instrument cluster (IC) control unit sends the request for switching on the daytime running lights via the user interface CAN, the central gateway and the interior CAN to the signal acquisition and actuation module (SAM) control unit.
The CDI control unit (N3/33) (with engine 651) or the CDI control unit (N3/40) (with engine 654) or the ME control unit (N3/34) (with engine 274) sends the "Engine running" signal over the drive train CAN (CAN C), the powertrain control unit (N127), the chassis CAN, the electronic ignition lock (EZS) control unit and the interior CAN to the signal acquisition and actuation module (SAM) control unit.
The Electronic Stability Program (ESP) control unit (N30/4) sends the vehicle speed via the chassis CAN, electronic ignition lock (EZS) control unit and interior CAN to the signal acquisition and actuation module (SAM) control unit.
The signal acquisition and actuation module (SAM) control unit evaluates the information. If the function requirements are fulfilled, it sends a request to switch on the daytime running lights over the interior CAN, the electronic ignition lock (EZS) control unit and the front end CAN to the left headlamp control unit and the right headlamp control unit.
Vehicles with code LG2 (LED Intelligent Light System):
The left headlamp control unit then actuates the daytime running lights in the left parking/standing/daytime running light (E1/1e13) via left headlamp LIN and left front actuation module, LED exterior lighting.
At the same time, the right headlamp control unit actuates the daytime running lights in the right parking/standing/daytime running light (E2/1e13) via right headlamp LIN and right front actuation module, LED exterior lighting.
The daytime running lights actuation is deactivated as soon as the illumination switch is turned to the standing light, manual driving lights, left parking light or right parking light position.
Vehicles without code LG2 (LED Intelligent Light System):
The signal acquisition and actuation module (SAM) control unit directly reads in the status of the illumination switch.
Function sequence for auto on/off driving lights
In the auto on/off driving lights, the low beams are automatically switched on or off.
The auto on/off driving lights are purely a comfort function and do not relieve the driver of the need to follow the operating instructions as prescribed by the road traffic regulations.
| Vehicles with code LG2 (LED Intelligent Light System): Behavior of exterior lighting when automatic driving lights are activated in daylight |
|||
|---|---|---|---|
| Start of trip | Standing lamp | Daytime running lamps | Low beam |
| Circuit 15R ON | OFF | OFF | OFF |
| Circuit 15 ON | OFF | OFF | OFF |
| "Engine running" signal set and vehicle speed > 3 km/h. | OFF | ON | OFF |
| End of trip | Standing lamp | Daytime running lamps | Low beam |
| Circuit 15R ON | OFF | OFF | OFF |
| "Engine running" signal set and vehicle speed > 3 km/h | OFF | ON | OFF |
| Vehicles without code LG2 (LED Intelligent Light System): Behavior of exterior lighting when automatic driving lights are activated in daylight |
|||
|---|---|---|---|
| Start of trip | Standing lamp | Daytime running lamps | Low beam |
| Circuit 15C OFF | OFF | OFF | OFF |
| Circuit 15C ON | OFF | OFF | OFF |
| Circuit 15R ON | OFF | OFF | OFF |
| Circuit 15 ON | OFF | OFF | OFF |
| "Engine running" signal | OFF | ON | OFF |
| End of trip | Standing lamp | Daytime running lamps | Low beam |
| "Engine running" signal | OFF | ON | OFF |
| Circuit 15R ON | OFF | OFF | OFF |
| Circuit 15C ON (driver door closed) | OFF | OFF | OFF |
| Circuit 15C ON (driver door open) | OFF | OFF | OFF |
| Circuit 15C OFF | OFF | OFF | OFF |
| Vehicles with code LG2 (LED Intelligent Light System): Behavior of exterior lighting when automatic driving lights are activated at night |
||
|---|---|---|
| Start of trip | Standing lamp | Low beam |
| Circuit 15R ON | ON | OFF |
| Circuit 15 ON | ON | OFF |
| "Engine running" signal set and vehicle speed > 3 km/h. | ON | On (high beams permissible) |
| End of trip At the end of a trip, overlaps may occur between the auto on/off driving lights and the headlamp switch-off delay. |
Standing lamp | Low beam |
| Circuit 15R ON | ON | OFF |
| "Engine running" signal set and vehicle speed > 3 km/h. | ON | On (high beams permissible) |
| Vehicles without code LG2 (LED Intelligent Light System): Behavior of exterior lighting when automatic driving lights are activated at night |
||
|---|---|---|
| Start of trip | Standing lamp | Low beam |
| Circuit 15C OFF | OFF | OFF |
| Circuit 15C ON | OFF | OFF |
| Circuit 15R ON | ON | OFF |
| Circuit 15 ON | ON | OFF |
| "Engine running" signal | ON | On (high beams permissible) |
| End of trip At the end of a trip, overlaps may occur between the auto on/off driving lights and the headlamp switch-off delay. |
Standing lamp | Low beam |
| "Engine running" signal | ON | On (high beams permissible) |
| Circuit 15R ON | ON | OFF |
| Circuit 15C ON (driver door closed) | ON | OFF |
| Circuit 15C ON (driver door open) | OFF | OFF |
| Circuit 15C OFF | OFF | OFF |
The low beams are switched on or off depending on the ambient brightness or depending on the activities of the windshield wiper system:
- Function sequence for automatic driving lights via light sensor (B38/1) (with code LA2 (Automatic driving lights)) or via humidity sensor/light sensor/rain sensor (B38/2) (with code JF1 (Rain sensor)) or via rain and light sensor with additional functions (B38/5) (with code HH4 (THERMOTRONIC automatic climate control))
- Function sequence for automatic driving lights via humidity sensor/light sensor/rain sensor (B38/2) (with code HH9 (Semi-automatically controlled air conditioning system, TEMPMATIC)) or via rain and light sensor with additional functions (B38/5) (with code HH4 (THERMOTRONIC automatic climate control))
- Function sequence for auto on/off driving lights over wiper activities
Function sequence for automatic driving lights via light sensor (B38/1) (with code LA2 (Automatic driving lights)) or via humidity sensor/light sensor/rain sensor (B38/2) (with code JF1 (Rain sensor)) or via rain and light sensor with additional functions (B38/5) (with code HH4 (THERMOTRONIC automatic climate control))
On model 447.6/7:
The ambient brightness is detected by the light sensor or by the humidity sensor/light sensor/rain sensor or by the rain and light sensor with additional functions. This sensor reads in the signals, evaluates them and sends a signal via the roof LIN (LIN B13) to the signal acquisition and actuation module (SAM) control unit. The signal acquisition and actuation module (SAM) control unit evaluates this signal and activates the low beams actuation.
Function sequence for automatic driving lights via humidity sensor/light sensor/rain sensor (B38/2) (with code HH9 (Semi-automatically controlled air conditioning system, TEMPMATIC)) or via rain and light sensor with additional functions (B38/5) (with code HH4 (THERMOTRONIC automatic climate control))
On Model 447.8:
The ambient brightness is recorded by the humidity sensor/light sensor/rain sensor or by the rain and light sensor with additional functions. This transmits a signal to the signal acquisition and actuation module (SAM) control unit via the roof LIN (LIN B13). The signal acquisition and actuation module (SAM) control unit evaluates this signal and activates the low beams actuation.
In the event of failure of the light sensor, of the humidity sensor/light sensor/rain sensor or of the rain and light sensor with additional functions, the automatic driving lights are not deactivated until the engine is switched off.
When the vehicle is being driven through a tunnel and if the wiper start suppression function is active, the auto on/off driving lights function remains switched on.
Function sequence for auto on/off driving lights over wiper activities
If the low beams are switched on or off due to the activities of the windshield wiper system, one refers to adverse weather light. The signal acquisition and actuation module (SAM) control unit controls the windshield wiper system.
When the windshield wiper system is activated for more than 20 s with a wipe cycle time of < 6 s, the signal acquisition and actuation module (SAM) control unit activates the low beam actuation. If the wipe cycles remain off for 60 s, the low beam actuation is deactivated.
If the wiper startup suppression function is canceled, the automatic driving lights remain active for an additional 60 s. Detailed information on the wiper startup suppression function can be found in the document "Windshield wipe, function".
Additional function requirements for headlamp range control:
- Driving lights ON (low beam or high beam)
Function sequence for headlamp range control
Vehicles with code LG2 (LED Intelligent Light System):
The automatic HRA [LWR] corrects the headlamp range of the vehicle headlamps in accordance with the load and the vehicle pitch motions caused by the vehicle dynamics.
The left headlamp control unit directly reads in the signals from the front axle level sensor (B22/2) and the rear axle level sensor (B22/3) and evaluates them.
The left headlamp control unit then directly actuates the left headlamp range adjustment actuator motor (E1/1m1) and the right headlamp range adjustment actuator motor (E2/1m1).
If the vehicle is moving at a constant speed, the automatic headlamp range adjustment system operates in "static mode" at a low adjustment speed. When the vehicle is accelerated, the "dynamic mode" is activated and the reaction time of the automatic headlamp range adjustment is significantly reduced. Depending on the speed change and additional signals such as brake pedal and accelerator pedal position, the "dynamic mode" is activated.
When the vehicle is standing automatic headlamp range adjustment is accomplished in the "dynamic mode".
Vehicles without code LG2 (LED Intelligent Light System):
The HRA [LWR] is installed as an item of passive safety equipment to prevent oncoming traffic from being dazzled.
The incline angle of the driving lights can be corrected by operating the headlamp range controller (S1/2s8).
The signal acquisition and actuation module (SAM) control unit directly actuates the left headlamp range adjustment actuator motor (E1m1) and the right headlamp range adjustment actuator motor (E2m1).
The left headlamp range adjustment actuator motor adjusts the headlamp unit in the left front lamp unit.
The right headlamp range adjustment actuator motor adjusts the headlamp unit in the right front lamp unit.
| Overview of exterior lights system components | GF82.10-S-9998TRF |